usb: core: switch bus numbering to using idr

USB bus numbering is based on directly dealing with bitmaps and
defines a separate list of busses.
This can be simplified and unified by using existing idr functionality.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index b35a6a52210f..6118a04f0b84 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -110,13 +110,6 @@ static const char format_endpt[] =
 /* E:  Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
   "E:  Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
 
-
-/*
- * Need access to the driver and USB bus lists.
- * extern struct list_head usb_bus_list;
- * However, these will come from functions that return ptrs to each of them.
- */
-
 /*
  * Wait for an connect/disconnect event to happen. We initialize
  * the event counter with an odd number, and each event will increment
@@ -618,6 +611,7 @@ static ssize_t usb_device_read(struct file *file, char __user *buf,
         struct usb_bus *bus;
         ssize_t ret, total_written = 0;
         loff_t skip_bytes = *ppos;
+        int id;
 
         if (*ppos < 0)
                 return -EINVAL;
@@ -628,7 +622,7 @@ static ssize_t usb_device_read(struct file *file, char __user *buf,
 
         mutex_lock(&usb_bus_list_lock);
         /* print devices for all busses */
-        list_for_each_entry(bus, &usb_bus_list, bus_list) {
+        idr_for_each_entry(&usb_bus_idr, bus, id) {
                 /* recurse through all children of the root hub */
                 if (!bus_to_hcd(bus)->rh_registered)
                         continue;